Hacker had access to terminal. How do I undo damage?

CiviB wrote:

My mom fell for a scam, and gave a hacker access to her laptop!

She called me for something technical and when i went into her screen I saw that she had some sort of screen share on, and the terminal was open. I immediately shut both, and then she told me about a call she had from Apple...

I have no idea what the creep did. What do I need to do to undo the damage?

Will wiping the hard drive help? Is there something simpler that would work?

After this, I'll be setting her up with a parental controlled account!

Are you having any issues?

Just because screen share and terminal was open does not in itself translate into hacker (?)

It would be more informative to know the the tech support she was sharing with and what was going on in the terminal...

You can always fall back by restoring from a backup—previous to the encounter.

How to use Time Machine to... restore your Mac: https://support.apple.com/en-us/HT201250

You're welcome. IMO it is the safest way to go.

I would follow the steps here:

What to do before you sell, give away, or trade in your Mac - Apple Support

This will wipe everything and then she can set the Mac up as new.